Tuning domain wall dynamics in a notched ferromagnetic nanostrip with Rashba effect.

Abstract

This work delineates a comprehensive investigation of the static and kinetic depinning of a domain wall in a notched ferromagnetic nanostrip. More precisely, we consider a 180° Bloch-type domain wall and examine its behavior under the action of an applied magnetic field, spin-polarized electric current, and Rashba field. Moreover, we assume an artificial notch positioned at the edges of the nanostrip, serving as a pinning site for the wall. We characterize domain walls' pinning and depinning dynamics in the steady-state regime by using the classical Schryer and Walker trial-function approach. The results demonstrate that the static depinning limits of external stimuli are more significant than the kinetic depinning. It is also observed that higher Rashba field strength increases the static depinning fields/currents while decreasing kinetic depinning ones. Furthermore, both static and kinetic depinning thresholds are elevated with higher damping, whereas an increase in the non-adiabatic spin-transfer parameter leads to a reduction. Finally, we present numerical illustrations of the analytical results, showing good qualitative agreement with the literature.